title: Acanthamoeba sp. promotes the survival and growth of Acinetobacter baumanii.
abstract: Acinetobacter baumanii, which may be found in water, is an important emerging hospital-acquired pathogen. Free-living amoebae can be recovered from the same water networks, and it has been shown that these protozoa may support the growth of other bacteria. In this paper, we have studied potential relationships between A. baumanii and Acanthamoeba species. Two strains of A. baumanii isolated from hospital water were co-cultivated with the trophozoites or supernatants of two free-living amoebae strains: Acanthamoeba castellanii or Acanthamoeba culbertsoni. Firstly, the presence of the amoebae or their supernatants induced a major increase in A. baumanii growth, compared with controls. Secondly, A. baumanii affected only the viability of A. culbertsonii, with no effect on A. castellanii. Electron microscopy observations of the cultures investigating the bacterial location in the protozoa showed persistence of the bacteria within cyst wall even after 60 days of incubation. In our study, the survival and growth of A. baumanii could be favored by Acanthamoeba strains. Special attention should consequently be paid to the presence of free-living amoebae in hospital water systems, which can promote A. baumanii persistence.
authors.affiliation: Laboratoire de parasitologie et mycologie médicale, Faculté de médecine et de pharmacie, Poitiers, France. estelle.cateau@chu-poitiers.fr
authors.forename: Estelle
authors.initials: E
authors.lastname: Cateau
authors.forename: Julien
authors.initials: J
authors.lastname: Verdon
authors.forename: Beatrice
authors.initials: B
authors.lastname: Fernandez
authors.forename: Yann
authors.initials: Y
authors.lastname: Hechard
authors.forename: Marie-Helene
authors.initials: MH
authors.lastname: Rodier
mesh_terms: D000048:Acanthamoeba / Q000382:microbiology* / Q000502:physiology; D048248:Acanthamoeba castellanii / Q000254:growth & development* / Q000502:physiology; D018920:Coculture Techniques; D003428:Cross Infection / Q000209:etiology* / Q000382:microbiology; D005618:Fresh Water / Q000382:microbiology* / Q000469:parasitology; D006801:Humans; D007362:Intensive Care Units; D050296:Microbial Viability